Re^2: Find element in array

[Sofie]

Thanks for your quick reply. I still don't get it to work, sorry I am really a beginner at this. The ultimate goal is to print out all the positions in the original array @DNA that has an invalid character. And then to count the number of characters that are invalid. How is the if statement looking or the invalid characters? How can I use the $-[0] to find the position of the invalid characters? Thanks again